Q.
A horizontal force of 10 N is necessary to just hold a block stationary against a wall. The coefficient of friction between the block and the wall is 0.2. The weight of the block is
A) 20 N
B) 50 N
C) 100 N
D) 2 N
Explanation
(d) Let, R be the normal contact force by wall on the block.
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$R = 10\ $N
$f_{L} = w\ \ and\ \ \ f = \mu R$
$\therefore\ \ \mu R = w$
$\Longrightarrow \ \ \ \ w = 0.2 \times 10 = 2\ N$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.